On the impact of unsynchronized interferers on multi-antenna OFDM systems

In this paper, the impact of interferers that are not synchronized in frequency is investigated in multi-antenna OFDM systems. Exact closed-form expressions for the outage probabilities are derived for two spatial linear receivers: the matched-filter (MF) receiver and the linear minimum-mean-square-error (LMMSE) receiver, assuming correlated frequency-selective Rayleigh fading channels and carrier frequency offsets (CFOs) between each interferer and the receiver. It is found that the CFOs have a negligible impact on the performance of the MF receiver, but a non-negligible impact on the performance of the LMMSE receiver for a range of realistic parameters. This theoretical analysis reveals valuable insights into practical implementation of such systems, and enables system designers to quantify the impact of the CFOs on the performance of the MF receiver and the LMMSE receiver.